This seems like it is a must read for anyone working on microbiomes: Frontiers | Microbiome Datasets Are Compositional: And This Is Not Optional | Microbiology Gloor GB, Macklaim JM, Pawlowsky-Glahn V and Egozcue JJ (2017) Microbiome Datasets Are Compositional: And This Is Not Optional. Front. Microbiol. 8:2224. doi: 10.3389/fmicb.2017.02224 Summary from the paper: Datasets …